Stage 3 consists of RS4 Turbochargers and induction pipes, RS4 fuel injectors with MTM adaptors, RS4 fuel pump, MTM’s full stainless steel exhaust system, high flow downpipes with flex couplings, stainless metallic sport catalytic converters, Bosch performance spark plugs, K&N air filter, sport y-hose, y-hose brace, sport bypass valves and simply the highest quality pressure hoses made to spec for MTM. We also appropriately modify the ECM software for this upgrade. Fit and finish of this kit is superb!